Removed the interface from hlfir.as_expr.

Author: vzakhari

flang/include/flang/Optimizer/HLFIR/HLFIROps.td

@@ -950,8 +950,8 @@ def hlfir_EndAssociateOp : hlfir_Op<"end_associate", [MemoryEffects<[MemFree]>]>
 }
 
 def hlfir_AsExprOp
-    : hlfir_Op<"as_expr", [DeclareOpInterfaceMethods<MemoryEffectsOpInterface>,
-                           fir_FortranObjectViewOpInterface]> {
+    : hlfir_Op<
+          "as_expr", [DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
   let summary = "Take the value of an array, character or derived variable";
 
   let description = [{
@@ -975,9 +975,6 @@ def hlfir_AsExprOp
   let extraClassDeclaration = [{
     // Is this a "move" ?
     bool isMove() { return getMustFree() != mlir::Value{}; }
-    // FortranObjectViewOpInterface methods:
-    mlir::Value getViewSource(mlir::OpResult) { return getVar(); }
-    std::optional<std::int64_t> getViewOffset(mlir::OpResult) { return 0; }
   }];
 
   let assemblyFormat = [{

flang/lib/Optimizer/Analysis/AliasAnalysis.cpp

@@ -551,6 +551,13 @@ AliasAnalysis::Source AliasAnalysis::getSource(mlir::Value v,
     assert(opResult.getOwner() == defOp && "v must be a result of defOp");
     ty = opResult.getType();
     llvm::TypeSwitch<Operation *>(defOp)
+        .Case<hlfir::AsExprOp>([&](auto op) {
+          // TODO: we should probably always report hlfir.as_expr
+          // as a unique source, and let the codegen decide whether
+          // to use the original buffer or create a copy.
+          v = op.getVar();
+          defOp = v.getDefiningOp();
+        })
         .Case<hlfir::AssociateOp>([&](auto op) {
           assert(opResult != op.getMustFreeStrorageFlag() &&
                  "MustFreeStorageFlag result is not an aliasing candidate");